Preheat oven to 400°F (200°C). Cut the top off the head of garlic to expose the cloves, drizzle with olive oil, wrap in foil, and roast for 40 minutes until soft. Allow to cool, then squeeze out the cloves and mash them slightly.

In a large mixing bowl, whisk together the flour, salt, yeast, and chopped rosemary.

Add the warm water and the mashed roasted garlic to the dry ingredients. Stir with a wooden spoon or spatula until a shaggy, sticky dough forms. Do not knead.

Cover the bowl tightly with plastic wrap or a clean kitchen towel. Let the dough rest at room temperature for 12 to 18 hours until it is bubbly and has doubled in size.

When ready to bake, place a Dutch oven or heavy covered pot into the oven and preheat to 450°F (230°C). Let the pot heat up empty for 30 minutes.

While the pot heats, turn the dough onto a floured piece of parchment paper. Gently shape it into a round loaf using floured hands.

Carefully remove the hot pot from the oven. Lift the parchment paper with the dough and place it directly inside the pot.

Cover with the lid and bake for 30 minutes.

Remove the lid and bake for another 10 to 15 minutes, until the crust is deep golden brown and crispy.

Remove the bread from the pot and let it cool on a wire rack for at least 30 minutes before slicing to ensure the texture is set.